1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
5 -- S Y S T E M . V A L _ L L U --
9 -- Copyright (C) 1992-2006, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 2, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
20 -- Boston, MA 02110-1301, USA. --
22 -- As a special exception, if other files instantiate generics from this --
23 -- unit, or you link this unit with other files to produce an executable, --
24 -- this unit does not by itself cause the resulting executable to be --
25 -- covered by the GNU General Public License. This exception does not --
26 -- however invalidate any other reasons why the executable file might be --
27 -- covered by the GNU Public License. --
29 -- GNAT was originally developed by the GNAT team at New York University. --
30 -- Extensive contributions were provided by Ada Core Technologies Inc. --
32 ------------------------------------------------------------------------------
34 -- This package contains routines for scanning modular Long_Long_Unsigned
35 -- values for use in Text_IO.Modular_IO, and the Value attribute.
37 with System
.Unsigned_Types
;
39 package System
.Val_LLU
is
42 function Scan_Raw_Long_Long_Unsigned
45 Max
: Integer) return System
.Unsigned_Types
.Long_Long_Unsigned
;
46 -- This function scans the string starting at Str (Ptr.all) for a valid
47 -- integer according to the syntax described in (RM 3.5(43)). The substring
48 -- scanned extends no further than Str (Max). Note: this does not scan
49 -- leading or trailing blanks, nor leading sign.
51 -- There are three cases for the return:
53 -- If a valid integer is found, then Ptr.all is updated past the last
54 -- character of the integer.
56 -- If no valid integer is found, then Ptr.all points either to an initial
57 -- non-digit character, or to Max + 1 if the field is all spaces and the
58 -- exception Constraint_Error is raised.
60 -- If a syntactically valid integer is scanned, but the value is out of
61 -- range, or, in the based case, the base value is out of range or there
62 -- is an out of range digit, then Ptr.all points past the integer, and
63 -- Constraint_Error is raised.
65 -- Note: these rules correspond to the requirements for leaving the pointer
66 -- positioned in Text_IO.Get
68 -- Note: if Str is empty, i.e. if Max is less than Ptr, then this is a
69 -- special case of an all-blank string, and Ptr is unchanged, and hence
70 -- is greater than Max as required in this case.
72 function Scan_Long_Long_Unsigned
75 Max
: Integer) return System
.Unsigned_Types
.Long_Long_Unsigned
;
76 -- Same as Scan_Raw_Long_Long_Unsigned, except scans optional leading
77 -- blanks, and an optional leading plus sign.
78 -- Note: if a minus sign is present, Constraint_Error will be raised.
79 -- Note: trailing blanks are not scanned.
81 function Value_Long_Long_Unsigned
82 (Str
: String) return System
.Unsigned_Types
.Long_Long_Unsigned
;
83 -- Used in computing X'Value (Str) where X is a modular integer type whose
84 -- modulus exceeds the range of System.Unsigned_Types.Unsigned. Str is the
85 -- string argument of the attribute. Constraint_Error is raised if the
86 -- string is malformed, or if the value is out of range.